In the News (Tue 31 Mar 15)

MarsClimateOrbiter was launched on a Delta 7425 (a Delta II Lite launch vehicle with four strap-on solid rocket boosters and a Star 48 (PAM-D) third stage).

The orbiter was to begin aerobraking, using the solar panel to provide resistance and continue until a 90 × 405 km orbit was achieved, nominally on 22 November1999, with periapsis at 89 N. The hydrazinethrusters would be used to change the orbit to a 2-hour, 421 km near-circular polar science mapping orbit on 1 December1999.

The Mars Surveyor '98 program is comprised of two spacecraft launched separately, the MarsClimateOrbiter (formerly the Mars Surveyor '98 Orbiter) and the Mars Polar Lander (formerly the Mars Surveyor '98 Lander).

The MarsClimateOrbiter was destroyed when a navigation error caused it to miss its target altiude at Mars by 80 to 90 km, instead entering the martian atmosphere at an altitude of 57 km during the orbit insertion maneuver.

MarsClimateOrbiter was launched on a Delta 7425 (a Delta II Lite launch vehicle with four strap-on solid-rocket boosters and a Star 48 (PAM-D) third stage).

MarsClimateOrbiter will be starting from an orbit much lower than Mars Global Surveyor - with an orbit period only one-third as long - so it will require much less aerobraking.

If MarsClimateOrbiter is launched within the first eight days of its launch period, it will be able to reach its final science-gathering orbit at least two weeks before Mars Polar Lander arrives.

Although the orbiter's transmitter may be on continuously during aerobraking, contact with Earth will not be possible during the aeropasses or when the spacecraft passes behind Mars as seen from Earth.

The MarsClimateOrbiter is due for launch on Dec. 10 on a Boeing Delta 2 launch vehicle from Cape Canaveral Air Station, Florida.

The launch of the MarsClimateOrbiter is scheduled to occur aboard a Boeing Delta II (7425) rocket on Dec. 10, 1998.

The 1998MarsClimateOrbiter and Mars Polar Lander missions are managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology, Pasadena, Calif. Lockheed Martin Astronautics, Denver, Colo. which built and operates the spacecraft, is JPL's industrial partner in the mission.

MarsClimateOrbiter was designed to function as an interplanetary weather satellite and a communications relay for Mars Polar Lander.

The orbiter carried two science instruments: a copy of an atmospheric sounder on the Mars Observer spacecraft lost in 1993, and a new, lightweight color imager combining wide- and medium-angle cameras.

The orbiter was to conduct a two year primary mission to profile the Martian atmosphere and map the surface.

During its primary mission, the orbiter was to monitor Mars atmosphere and surface globally on a daily basis for one Martian year (two Earth years), observing the appearance and movement of atmospheric dust and water vapor, as well as characterizing seasonal changes of the planet's surface.

Unfortunately, MarsClimateOrbiter burned up in the Martian atmosphere on September 23, 1999, due to a metric conversion error that caused the spacecraft to be off course.

grin.hq.nasa.gov /ABSTRACTS/GPN-2000-000498.html (231 words)

Mars Climate Orbiter(Site not responding. Last check: 2007-10-23)

The MCO was to have used a technique called aerobraking, which uses a planet's atmospheric friction to reduce the spacecraft's velocity (See Appendix 1).

"MarsClimateOrbiter's first assignment after it completes aerobraking will be to serve as the communications relay for its sibling spacecraft, Mars Polar Lander, set to land near the south pole on December 3." (p3, [5]).

The root cause for the loss of the MarsClimateOrbiter in September 1999, was due to the failure to convert the outputted Imperial measurements to the required metric measurements, within a specific piece of ground software.

The MarsClimateOrbiter, a $125-million spacecraft described as the National Aeronautics and Space Administration's (NASA) first interplanetary weather satellite, disappeared as it attempted to establish an orbit around Mars on September 23, 1999.

Mars Reconnaissance Orbiter was the first spacecraft designed from the beginning for aerobraking to place it into the desired orbit around Mars.

During its two-year primary science mission, the Mars Reconnaissance Orbiter was to conduct eight different science investigations at Mars, involving global mapping, regional surveying, and high-resolution targeting of specific spots on the surface.

MCS (MarsClimate Sounder) - This radiometer functioned as an atmospheric profiler to detect vertical variations of temperature, dust, and water vapor concentrations in the Martian atmosphere.

The Mars Surveyor '98 program is comprised of two spacecraft launched separately, the MCO (MarsClimateOrbiter, formerly the Mars Surveyor '98 Orbiter) and the MPL (Mars Polar Lander, formerly the Mars Surveyor '98 Lander).

The MarsClimateOrbiter was destroyed when a navigation error caused it to miss its target altitude at Mars by 80 to 90 km, instead entering the Martian atmosphere at an altitude of 57 km during the orbit insertion maneuver.

The MarsClimateOrbiter was part of an extended series of missions conducted by NASA to expore Mars during an extended period when Mars and Earth's orbits brought them into relative proximity.

Subsequent analysis of the failure determined that the principle cause of the failure was confusion in units, instead of sending thrust information to the orbiter in Newtons, the instructions were in pounds, a factor of 2.2 times greater.

These instructions were used by the orbiter's earth based navigation controllers to adjust the craft's aspect during the voyage in order to compensate for changes caused by the assymmetry of the orbiter and pressure from the solar wind on the panels.

MarsClimateOrbiter, the first of the two Mars Surveyor 1998 spacecraft (the other being the Mars Polar Lander), was successfully launched on December 11, 1998 by a Delta II 7425 launch vehicle.

Its mission was to do extensive research of Mars' atmosphere, weather and climate, i.e., observe wind, water vapor, volatiles, carbon dioxide budget, clouds etc. Moreover, it should have served as relay for the Mars Polar Lander.

MarsClimateOrbiter finally got lost when it probably came to close to planetMars during its MarsOrbit Insertion manouver on September 23, 1999.

NASA engineers confusing metric units with English units are to blame for a navigation error that may have sent the $125 million MarsClimateOrbiter into a suicide path with the Martian atmosphere on September 23, a Jet Propulsion Laboratory review board announced Thursday.

The probe was to enter a 160 km x 38600 km polar orbit around Mars on September 23,1999, and use aerobraking to reach a 373 km x 437 km x 92.9 degree sun-synchronous mapping orbit by November 23 1999.

While the MarsOrbit Insertion burn began as planned on September 23, 1999 at 08:50 GMT, no signal was received after the spacecraft went behind the planet.

MarsClimateOrbiter was equipped with a MARCI colour imager for mapping and weather studies; a PMIRR radiometer; and a UHF communications system which would also relay data from the (equally unsuccessful) Mars Polar Lander, scheduled for launch in January 1999.

www.astronautix.com /details/mar12378.htm (398 words)

Wright Center for Science Education at Tufts University(Site not responding. Last check: 2007-10-23)

In addtion to collecting data, the Orbiter will act as a relay station for five years, assisting in data transmission to and from the Mars Polar Lander, as well as the 2001 Lander mission.

NASA's MarsClimateOrbiter is believed to be lost due to a suspected navigation error.

Unfortunately for MCO, the root cause was not caught by the processes in place in the MCO project.

Mars Surveyor 98 is actually two missions whose total price tag is about the same as Mars Pathfinder.

The "Volatiles and Climate History" theme for the 1998Mars Surveyor missions was recommended by the Mars Science Working Group and is aligned directly with NASA''s Mars exploration strategy for the next decade focusing on: Evidence of past or present life, Climate, and Resources.

The science complement for the 1998 lander includes: the Mars Volatile and Climate Surveyor (MVACS) integrated lander payload with Dr. David Paige of UCLA as Principal Investigator, the Mars Descent Imager (MARDI) with Dr.